For some time, it has been recognized in the prior art that controlled fuel injection, particularly that of the electronic type, is best suited for meeting the often conflicting demands of fuel economy, high engine performance, and allowable emissions in modern automobiles. Fuel injectors, on which electrically controlled fuel injection systems rely, essentially consist of three basic parts, i.e., an electromagnet, a needle valve, and a nozzle. The electromagnet is activated, for example, by a signal from an electronic control unit which moves the injector's needle valve sufficiently away from the opening in the nozzle to allow the injection or delivery of fuel in the form of a fine spray. The exact amount of fuel required for any given operating condition can be introduced based on information obtained from data delivered to the control unit from sensors located at multiple points throughout the engine and exhaust system. The result is an extremely efficient method for controlling engine performance.
Despite their superior performance, fuel injectors possess certain deficiencies which detract from their overall utility. Perhaps the most significant of these deficiencies is the tendency for unwanted deposits to accumulate in the nozzle area, thus resulting in nozzle clogging which causes rough idling, as well as hesitation of the engine during acceleration. In this regard, injector nozzles are manufactured to extremely fine tolerances, and even small amounts of foreign particles tend to result in their malfunction. Additionally, poor fuel quality, as well as ordinary operating conditions tend to be responsible for the unwanted accumulation of varnishes and other contaminants of the type described. These accumulations must be removed periodically if continued optimum performance of the injectors, and hence the engine, is to be achieved.
There is currently known in the prior art a wide range of fuel injector cleaning systems which employ any one of a variety of different cleaning techniques. The cleaning technique employed by one prior art cleaning system involves pouring a quantity of cleaning fluid directly into the gas tank of the automobile. The cleaning fluid mixes with the gasoline, and ultimately reaches the fuel injectors via the circulation of the gasoline through the fuel system. However, because of the requirement that the cleaning fluid formulation does not corrode the rubber hosing leading from the fuel tank to the fuel injectors, the formulation is relatively dilute, particularly when diluted by a significant amount of gasoline in the tank. As will be recognized, such dilution seriously compromises the efficacy of the formulation in dissolving contaminant deposits in the engine.
In view of the shortcomings of the above-described cleaning technique, a variety of cleaning systems/techniques have been developed in the prior art for injecting a more concentrated cleaning fluid solution directly into the fuel rail to which the fuel injectors are connected. In one such prior art system, the cleaning fluid is contained within a pressurized aerosol can which is connected to the fuel rail through a pressure regulator. However, these types of prior art cleaning systems have deficiencies relating to the use of aerosols which may be ozone unfriendly, the common inability to deliver all of the fluid in the aerosol can, the higher pressure at which the aerosol is typically provided (i.e., about 120 psi), the cost of the pressurized aerosol can, and the wear imposed on the plastic/rubber pieces of the pressure regulator of the system as the cleaning fluid passes therethrough.
Another currently known prior art cleaning system/technique eliminates the use of the pressurized can, instead making use of a pressurized air supply typically found in automotive shops. More particularly, a cylinder is filled with a quantity of cleaning fluid, with a pressurized air source then being introduced at one end of the cylinder to facilitate the discharge of pressurized cleaning fluid from the other end thereof. An in-line pressure gauge is typically disposed within the discharge line. However, these types of prior art cleaning systems/techniques also suffer from certain drawbacks. These deficiencies include the common need to transfer the cleaning fluid from its original container into the cylinder of the cleaning system. Such transfer is undesirable due to the highly flammable and corrosive nature of the cleaning fluid and the risk of inadvertent spillage during the transfer process. Additionally, the in-line pressure gauge as well as other components in such cleaning systems are extremely difficult to replace. In this respect, fuel line pressure specifications vary with the make of the automobile engine, thus often requiring the substitution of the pressure gauge with one adapted to provide pressure readings in a different range. Finally, because they comprise numerous components and adapters, these types of cleaning systems are often expensive to assemble, difficult to use, and incapable of performing alternative functions such as engine decarbonizing and fuel pressure checks. Though certain prior art cleaning systems may be configured so as to avoid the need to transfer the cleaning fluid from one container to another, they are still deficient in that the user thereof is subjected to substantial exposure to the fumes of the cleaning fluid during the process of setting up the cleaning system.
The present invention addresses and overcomes these and other deficiencies of prior art cleaning systems/techniques. More particularly, in the present invention, use is made of a cleaner container or canister which is provided with a safety cap adapted to have a single opening formed therein on demand into which pressurized air is injected and cleaning fluid is discharged, thus avoiding the need of pouring the highly flammable and corrosive cleaning fluid from one container to another, or exposing the user to the fumes from the cleaning fluid. The source of pressurized air for the present invention is that found in the shop (i.e., "shop air"), and is regulated to a desired pressure level. A connecting manifold is provided in the present invention which allows for the direct connection/disconnection of the pressurized air source, cleaning fluid canister, discharge line and pressure gauge thereto. Any of the four (4) ports of the manifold can be connected/disconnected without disturbing connections to the other three (3) ports. For example, where the fuel pressure should be more properly measured in another range, the pressure gauge can be quickly and easily replaced without removing the connection to the cleaning fluid canister. Also provided in the manifold is a shut-off valve and a safety check valve. The shut-off valve allows for the use of the present invention for other applications, including engine decarbonizing and fuel pressure checks. The safety check valve prevents the interior of the cleaning fluid canister from being pressurized in the event the same is not fully threadably engaged to the manifold.
As such, the present invention has the advantages of being compact, easy to use, safe, cheaper to build, and avoiding the need for expensive and/or pressurized containers, while substantially eliminating the risk of spilling the highly flammable and corrosive cleaning fluid since it need not be transferred from one container to another. The present invention also avoids the exposure of the user to the cleaning fluid fumes, allows for the quick and easy connection/disconnection of components, and preserves the life of the pressure regulator by avoiding the exposure thereof to the corrosive cleaning fluid. These, and other advantages associated with the present invention, will be discussed in more detail below.